i'd like some advice

first of all, are all mini-itx-boards linux & fedora/amahi compatible?
second: i'm looking for a mainboard with integrated cpu and graphics...
important: low power consumption, low cost
unimportant: performance (only basic amahi-usage...meaning the included server functions like file,print,dhcp,dns etc)
Any recommendations?
Lastly i'd like to hear confirmation on this matter:
i read that 3,5 hdd's on ide/sata are massive power consumers, however external usb-drives are using a lot less (like half) and 2,5 hdd's only as much as 2-5 watts..can anyone confirm that?
maybe also advice..? i'll need around 1tb+ storage. i have a limited budget, so many 160gb 2,5 hdd's won't do.
thought about a small one for the system itself and a 1,5tb usb wd hdd for storage...any comments/suggestions?
thanks for any kind of help in advance

- faxij